EV/Dryer Transfer Switch Load Calc

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ESolar

Senior Member
Location
Eureka, CA Humboldt County
Occupation
Electrician/Contractor
What is the answer to this question and where in the NEC can I find it? The AHJ is stating that a (DPDT) transfer switch (between dryer and EV) on a 40 amp circuit requires both the dryer and the EV in load calculations. For example, a 40 Amp circuit to a transfer switch between a 5000VA dryer (21A) and a 32A EV (40A continuous) requires both the dryer and the EV both occur in the load calcs. The AHJ was suggesting (she's not certain) that an automatic switch might allow one load (the larger) to be used in the calcs, but that a manual switch requires that both be used. As I see it, the larger of the two should be used in all cases, and the manual switch is the real guarantee that only one load is active, whereas the automatic switch is a blackbox that could fail. But the code may see it differently.
 
Are you planning on a regular DPDT switch or an automatic like this one
 
Are you planning on a regular DPDT switch or an automatic like this one
Didn't know about this. Suppose it works if the dryer is in the garage. The dryer is still only a 30A 240v circuit.
 
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